Improved Measurement of CP Asymmetries in B0 to (ccbar)K0(*) Decays

Improved Measurement of CP Asymmetries in B0 to (ccbar)K0(*) Decays
Title Improved Measurement of CP Asymmetries in B0 to (ccbar)K0(*) Decays PDF eBook
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Release 2005
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We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 227 x 106 [Upsilon](4S) → B{bar B} decays collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The amplitude of the CP asymmetry, sin2[beta] in the Standard Model, is derived from decay-time distributions from events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B° or {bar B}° from its decay products. We measure sin2[beta] = 0.722 ± 0.040(stat) ± 0.023(syst) in agreement with the Standard Model expectation.

Improved Measurement of CP Observables in B- to D0_CP K- Decays

Improved Measurement of CP Observables in B- to D0_CP K- Decays
Title Improved Measurement of CP Observables in B- to D0_CP K- Decays PDF eBook
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Pages 8
Release 2008
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We present a study of the decay B− 2!D{sub (CP)}°K− and its charge conjugate, where D{sub (CP)}° is reconstructed in both a non-CP flavor eigenstate and in CP (CP-even and CP-odd) eigenstates, based on a sample of 382 million [Upsilon](4S) 2!B{bar B} decays collected with the BABAR detector at the PEP-II ee− storage ring. We measure the direct CP asymmetries A{sub CP±} and the ratios of the branching fractions R{sub CP±}: A{sub CP+} = 0.27 ± 0.09(stat) ± 0.04(syst), A{sub CP-} = -0.09 ± 0.09(stat) ± 0.02(syst), R{sub CP+} = 1.06 ± 0.10(stat) ± 0.05(syst), R{sub CP-} = 1.03 {+-} 0.10(stat) {+-} 0.05(syst). These results will help to better constrain the gamma phase parameter of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

Improved Measurements of CP-Violating Asymmetries in B[sup 0] --] [pi][sup +][pi][sup -] Decays

Improved Measurements of CP-Violating Asymmetries in B[sup 0] --] [pi][sup +][pi][sup -] Decays
Title Improved Measurements of CP-Violating Asymmetries in B[sup 0] --] [pi][sup +][pi][sup -] Decays PDF eBook
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Pages
Release 2004
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ISBN

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The authors present preliminary updated measurements of the CP-violating parameters S[sub [pi][pi]] and C[sub [pi][pi]] in B[sup 0] --> [pi][sup +][pi][sup -] decays. Using a sample of 227 million [Upsilon](4S) --> B[bar B] decays collected with the BaBar detector at the PEP-II asymmetric-energy e[sup +]e[sup -] collider at SLAC, they observe 467 [+-] 33 signal decays and measure S[sub [pi][pi]] = -0.30 [+-] 0.17(stat)[+-] 0.03(syst), and C[sub [pi][pi]] = -0.09 [+-] 0.15(stat)[+-] 0.04(syst).

Measurement of CP Asymmetries and Branching Fractions in B0 -] Pi+ Pi-, B0 -] K+ Pi-, B0 -] Pi0 Pi0, B0 -] K0 Pi0 and Isospin Analysis of B -] Pi Pi Decays

Measurement of CP Asymmetries and Branching Fractions in B0 -] Pi+ Pi-, B0 -] K+ Pi-, B0 -] Pi0 Pi0, B0 -] K0 Pi0 and Isospin Analysis of B -] Pi Pi Decays
Title Measurement of CP Asymmetries and Branching Fractions in B0 -] Pi+ Pi-, B0 -] K+ Pi-, B0 -] Pi0 Pi0, B0 -] K0 Pi0 and Isospin Analysis of B -] Pi Pi Decays PDF eBook
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Pages 27
Release 2008
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ISBN

Download Measurement of CP Asymmetries and Branching Fractions in B0 -] Pi+ Pi-, B0 -] K+ Pi-, B0 -] Pi0 Pi0, B0 -] K0 Pi0 and Isospin Analysis of B -] Pi Pi Decays Book in PDF, Epub and Kindle

The authors present preliminary results of improved measurements of the CP-violating asymmetries and branching fractions in the decays B° →??−, B° → K+?−, B° →?°?°, and B° → K°?°. This update includes all data taken at the?(4S) resonance by the BABAR experiment at the asymmetric PEP-II B-meson factory at SLAC, corresponding to 467 ± 5 million B{bar B} pairs. They find S{sub??} = -0.68 ± 0.10 ± 0.03, C{sub??} = -0.25 ± 0.08 ± 0.02,?{sub K{sub?}} = -0.107 ± 0.016{sub -0.004}, {sup +0.006}, C{sub?°?°} = -0.43 ± 0.26 ± 0.05,?(B° →?°?°) = (1.83 ± 0.21 ± 0.13) x 10−6,?(B° → K°?°) = (10.1 ± 0.6 ± 0.4) x 10−6, where the first error is statistical and the second is systematic. They observe CP violation with a significance of 6.7? in B° → {pi}− and 6.1? in B° → K+{pi}−. Constraints on the Unitarity Triangle angle? are determined from the isospin relation between all B → {pi}{pi} rates and asymmetries.

Improved Measurement of CP Violation in Neutral BDecays to \ccbar S

Improved Measurement of CP Violation in Neutral BDecays to \ccbar S
Title Improved Measurement of CP Violation in Neutral BDecays to \ccbar S PDF eBook
Author
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Pages 7
Release 2007
Genre
ISBN

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The authors present updated measurements of time-dependent CP asymmetries in fully-reconstructed neutral B decays to several CP eigenstates containing a charmonium meson. The measurements use a data sample of (383 ± 4) x 106 [Upsilon](4S) → B{bar B} decays collected with the BABAR detector at the PEP-II B factory. They determine sin2[beta] = 0.714 ± 0.032(stat) ± 0.018(syst) and.

Measurement of CP Asymmetries in B0-]Ks Pi0 Pi0 Decays

Measurement of CP Asymmetries in B0-]Ks Pi0 Pi0 Decays
Title Measurement of CP Asymmetries in B0-]Ks Pi0 Pi0 Decays PDF eBook
Author J. C. Chen
Publisher
Pages 17
Release 2005
Genre
ISBN

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The authors present a preliminary measurement of the time-dependent CP asymmetry for the neutral B-meson decay into the CP = +1 final state K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}, with K{sub S}{sup 0} {yields} {pi}{sup +}{pi}{sup -} and {pi}{sup 0} {yields} {gamma}{gamma}. They use a sample of approximately 227 million B-meson pairs recorded at the {Upsilon}(4S) resonance by the BABAR detector at the PEP-II B-Factory at SLAC. From a maximum likelihood fit they extract the mixing-induced CP-violation parameter S{sub K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}} = 0.84 {+-} 0.71(stat) {+-} 0.08(syst) and the direct CP-violation parameter C{sub K{sub S}{sup 0}}{pi}{sup 0}{pi}{sup 0} = 0.27 {+-} 0.52(stat) {+-} 0.13(syst), where the first uncertainty is statistical and the second systematic.

Measurements of Time-dependent CP Asymmetries in B0 --] D(*)+D(*)- Decays

Measurements of Time-dependent CP Asymmetries in B0 --] D(*)+D(*)- Decays
Title Measurements of Time-dependent CP Asymmetries in B0 --] D(*)+D(*)- Decays PDF eBook
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Pages 13
Release 2009
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ISBN

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We present new measurements of time-dependent CP asymmetries for B° --> D{sup (*)+}d{sup (*)-} decays using (467 ± 5) x 106 B{bar B} pairs collected with the BABAR detector located at the PEP-II B Factory at the Stanford Linear Accelerator Center. We determine the CP-odd fraction of the B° --> D*D*− decays to be R(up tack) = 0.158 ± 0.028 ± 0.006 and find CP asymmetry parameters for the CP-even component of the decay S+ = -0.76 ± 0.16 ± 0.04 and C+ = 0.00 ± 0.12 ± 0.02. We measure S = -0.63±0.36±0.05 and C = -0.07±0.23±0.03 for B° --> DD−, S = -0.62±0.21±0.03 and C = 0.08 ± 0.17 ± 0.04 for B° --> D*+D−, and S = -0.73 ± 0.23 ± 0.05 and C = 0.00 ± 0.17 ± 0.03 for B° --> D+D*−. For the B° --> D*{sup ±}D{sup {-+}} decays, we also determine the CP-violating asymmetry A = 0.008 ± 0.048 {+-} 0.013. In each case, the first uncertainty is statistical and the second is systematic. The measured values for the asymmetries are all consistent with the Standard Model.